3GPP (3rd Generation Partnership Project) and the OMA (Open Mobile Alliance) specify the so-called Multimedia Messaging Service (MMS) for transmitting data, in particular multimedia data objects, from a first to a second mobile telephone or mobile radio device in a mobile radio communication network. Should a first user wish to send a second user a useful data object, for example in the form of an image or a music file, the user uses a (first) mobile telephone to send a multimedia message (MM) with the useful data object to a switching component in the communication network, which comprises at least one MMS relay server. A multimedia message (MM) can also contain a plurality of useful data objects. As a special service, the MMS provider can individually adapt the at least one useful data object to be delivered to the characteristics or capabilities of the second mobile telephone before sending a further message (hereafter referred to as a “recipient notification message”) to the second mobile telephone of the second user with the information that a multimedia message (MM) with at least one useful data object available for downloading. One disadvantage of such a method is that the recipient (in this instance the second user) of a recipient notification message or a multimedia message (MM) with at least one useful data object is unable to identify whether and how the transmission message (hereafter referred to as the multimedia message (MM)) or the useful data object contained therein has been modified and whether the possibly modified useful data object can still be used.